AFAIK Public Folders arent supported by Exchange Active Sync, which is licensed by Scalix. EAS is just a view to one mailbox. There are 3rd-Party-Solutions for Exchange. And of course its possible to Sync the folders to the mailbox. This would also require a 3rd-Party-Tool (or someone who writes a sync script for the API)
Joako, how does your post relate to the ActiveSync/Public Folder topic? If you are looking for announcements you are in the wrong section. The rumours area is called "Feedback" here.